1 iptables -t filter -A INPUT -p dccp --sport 1234 --dport 5678 -j ACCEPT
2 iptables -t filter -A INPUT -p dccp --dccp-types DATA,CLOSEREQ -j DROP
3 iptables -t filter -A INPUT -p dccp ! --dccp-types RESET,SYNC -j REJECT
4 iptables -t filter -A INPUT -p dccp --dccp-option 100 -j ACCEPT
5 iptables -t filter -A INPUT -p dccp ! --dccp-option 99 -j DROP